1. Field of the Invention
The present invention relates to systems that communicate across computer networks. More specifically, the present invention relates to a method and apparatus for dynamically configuring network communications parameters for an application.
2. Related Art
The explosion of broadband communications has helped the Internet become a viable distribution mechanism for multimedia and high quality video. Prior to broadband, conventional modems were much too slow for the large file sizes that video demands. Now that more and more people have broadband connections and are requesting ever larger items of content, bandwidth and server utilization is quickly becoming a bottleneck on the distribution end. For example, in some cases, extraordinary events have brought online news sites to a virtual standstill as people flocked to them to retrieve video of the events.
Some companies have tried to solve this problem by creating distributed content delivery networks. In a distributed content delivery network, once a client has received a file, that client becomes a potential server for that file to other clients. This is a great advantage because as clients download the content, the number of potential servers for the content grows. In this way, the classic bottleneck caused by many clients trying to retrieve the same content from a single server is virtually eliminated.
However, distributed content delivery networks suffer from a number of problems. While distributed content delivery networks have alleviated bandwidth bottlenecks at server locations, they have created bandwidth congestion at many client sites. Moreover, a large percentage of current broadband connections provide asymmetrical bandwidth. For example, a typical DSL or Cable Modem connection offers data transfer at the rate of 384 Kbps to 1.5 Mbps downstream, but only 128 Kbps upstream. Hence, it is not uncommon for the entire upstream bandwidth to be consumed by serving one piece of content to one peer.
Asymmetrical bandwidth can cause wasted bandwidth and decreased performance in many situations. For example, suppose a peer is receiving content at 512 Kbps from a server, and during this download, the peer receives a request to send the content to a remote peer. In response to the request, the peer starts sending the content to the remote peer. This outgoing content consumes almost the entire outgoing bandwidth, which causes a delay in sending the packet acknowledgements for the incoming packets of content that the peer is receiving from the server. Because the server that is sending the content to the peer does not receive packet acknowledgements in a timely manner, it reduces the rate at which it sends out the content to the peer. Consequently, in this situation, the saturation of the outgoing bandwidth actually degrades the performance of the incoming bandwidth.
In some cases, the distributed content delivery network application interferes with tasks that the user of the machine is trying to accomplish. For example, while the distributed content delivery network application is busy sending and receiving content, the user might be forced to wait an extra long period of time to load a web page or download email. Note that processor and memory resources are also used by distributed content delivery networks. Hence, queries can take an extra long time to execute.
What is needed is a method and an apparatus for distributed content delivery without the problems described above.